TV Mounts & Brackets
K&M 24150 MKII Speaker Mount
K&M 24150 MKII Speaker Mount, Box Mount for Vertical Truss Systems, Pipe-clamp suitable for diameters from 45 to 55 mm, Suitable for loudspeaker boxes with flange bushing of 36 mm, Selectable bolt spacing: 316/383/451 mm, Material: Steel, Swivel...
https://www.bizrate.co.uk/tvmounts_brackets/k-m-24150-mkii-speaker-mount-oid8793686791.html